For the purposes of the present document, the following terms and definitions apply:
Basic Call State Model (BCSM):
BCSM provides a high-level model of GMSC- or MSC/VLR-activities required to establish and maintain communication paths for users. As such, it identifies a set of basic call activities in a GMSC or MSC/VLR and shows how these activities are joined together to process a basic call.
Call Control Function (CCF):
Call Party Handling (CPH) Information Flow:
Any of the Disconnect Leg, Move Leg or Split Leg information flows.
A call segment contains one or more legs that are controlled by the same CS_gsmSSF instance. The call parties in the same call segment can communicate with each other (using a conference bridge if necessary). Call segments are identified by a number, eg. CSID1 is the call segment with id number 1.
Call Segment Association (CSA):
A CSA contains one or more call segments. Legs can be moved between call segments within the CSA. There is a single CAP dialogue between the CSA and the gsmSCF.
Detection Points (DP):
points in processing at which notifications (to the service logic) can occur and transfer of control (to the gsmSCF) is possible are called Detection Points (DPs).
Dialled Service CAMEL Subscription Information (D-CSI):
D-CSI identifies the subscriber as having originating CAMEL dialled services.
MSC which is either an MSC invoking a standardized Call Forwarding supplementary service or Call Deflection supplementary service; or an MSC invoking a CAMEL based call forwarding service.
Gateway MLC (GMLC):
functional entity that allows external LCS Clients to request real-time information about a Mobile Station. The information that can be requested from the GMLC is:
location of Mobile Station
See TS 23.271
and TS 25.305
or TS 43.059
for information on the GMLC.
information defining the location of a mobile station, coded according to ITU-T Recommendation Q.763 
. The derivation of this information from other information defining the location of a mobile station is a network operator option. If an entity derives the geodetic information it shall also provide the equivalent geographical information.
GPRS CAMEL Subscription Information (GPRS-CSI):
information defining the location of a mobile station, coded according to TS 23.032
GPRS-CSI identifies the subscriber as having GPRS CAMEL services.
A dialogue between the gprsSSF and the gsmSCF. A single GPRS Dialogue may consist of one or more TCAP dialogues. Only one TCAP dialogue shall exists at one point in time for one gprsDialogue.
GPRS Service Switching Function (gprsSSF):
functional entity that interfaces the SGSN to the gsmSCF. The concept of the gprsSSF is derived from the IN SSF, but uses different triggering mechanisms because of the nature of the mobile network.
GPRS session starts when the GPRS subscriber attaches to the GPRS data network. It ends when the GPRS subscriber detaches from the GPRS data network.
GSM Service Control Function (gsmSCF):
functional entity that contains the CAMEL service logic to implement OSS. It interfaces with the gsmSSF, the gsmSRF, the GMLC and the HLR.
GSM Service Switching Function (gsmSSF):
functional entity that interfaces the MSC or GMSC to the gsmSCF. The concept of the gsmSSF is derived from the IN SSF, but uses different triggering mechanisms because of the nature of the mobile network.
GSM Specialised Resource Function (gsmSRF):
functional entity which provides various specialized resources. It interfaces with the gsmSCF and with the MSC. This entity is defined in ITU-T Recommendation Q.1224 
with variations defined in the present document.
MSC which provides CAMEL support for incoming trunk calls.
indicates the location of the Mobile Station. The provision of location information is independent of the MS status. As part of the location information, an indication of the age of this information may be delivered.
Mobile Originating Short Message Service CAMEL Subscription Information (MO-SMS-CSI):
MO-SMS-CSI identifies the subscriber as having MO SMS CAMEL services. MO-SMS-CSI (CAMEL Phase 4) is identical to SMS-CSI (CAMEL Phase 3).
Mobile Station State:
similar to Subscriber State, but associated only with a Mobile Station, not with a subscriber.
Mobile Terminating Short Message Service CAMEL Subscription Information (MT-SMS-CSI):
MT-SMS-CSI identifies the subscriber as having MT SMS CAMEL services.
Mobility Management event CAMEL Subscription Information (M-CSI):
M-CSI identifies the subscriber as having Mobility Management event notification CAMEL services.
Mobility Management event GPRS CAMEL Subscription Information (MG-CSI):
MG-CSI identifies the GPRS subscriber as having Mobility Management event notification CAMEL services.
NA (North American):
prefix attached to certain information items used by North American PLMNs in connection with routing a call to a preferred or dialled long distance carrier.
Network CAMEL Service Information (N-CSI):
N-CSI identifies services offered on a per-network basis by the serving PLMN operator for all subscribers.
Originating Basic Call State Model (O-BCSM):
originating half of the BCSM. The O-BCSM corresponds to that portion of the BCSM associated with the originating party.
Originating CAMEL Subscription Information (O-CSI):
O-CSI identifies the subscriber as having originating CAMEL services.
Point In Association (PIA):
PIAs identify MSC/VLR or SGSN activities associated with one or more basic association/connection states of interest to OSS service logic instances.
Point In Call (PIC):
PICs identify MSC/VLR (GMSC) activities associated with one or more basic call/connection states of interest to OSS service logic instances.
Service Key identifies to the gsmSCF the service logic. The Service Key is administered by the HPLMN, and is passed transparently by the VPLMN/IPLMN to the gsmSCF. The Service Key is a part of the T/O/VT/D/GPRS/SMS/M-CSI.
functional entity that performs location information retrieval.
Short Message Control Protocol (SM-CP):
Short Message Service Centre (SMSC):
Protocol between the MSC or SGSN and the MS. This protocol, which is specified in TS 24.011
, is used to carry RPDU elements between the MSC or SGSN and the MS.
also abbreviation SC is used for SMSC.
Supplementary Service Notification CAMEL Subscription Information (SS-CSI):
SS-CSI identifies the subscriber as having supplementary service invocation notification CAMEL services.
Terminating Basic Call State Model (T-BCSM):
terminating half of the BCSM. The T-BCSM corresponds to that portion of the BCSM associated with the terminating party.
Terminating CAMEL Subscription Information (in the GMSC) (T-CSI):
T-CSI identifies the subscriber as having terminating CAMEL services in the GMSC.
Translation Information Flag (TIF-CSI):
TIF-CSI is a flag in the CAMEL subscriber data which indicates that when the subscriber registers a forwarded-to number, that the HLR shall not attempt to perform any translation, number format checks, prohibited FTN checks, call barring checks.
Trunk Originated CAMEL Service Information (TO-CSI):
TO-CSI identifies services offered by the PLMN operator to all incoming calls on a specific MSC trunk.
USSD CAMEL Subscription Information (U-CSI):
U-CSI identifies a set of subscriber specific mappings from a USSD service code to a gsmSCF address.
USSD General CAMEL Service Information (UG-CSI):
UG-CSI globally identifies a set of mappings from a USSD service code to a gsmSCF address. The global mapping applies to all HPLMN subscribers. If, for a particular service code, both U-CSI and UG-CSI are applicable then the U-CSI shall take precedence.
VMSC Terminating CAMEL Subscription Information (VT-CSI):
VT-CSI identifies the subscriber as having terminating CAMEL services in the VMSC.
Abbreviations used in the present document are listed in TR 21.905
For the purposes of the present document, the following abbreviations apply:
Basic Call State Model
Customized Applications for Mobile network Enhanced Logic
Call Party Handling
Call Segment Association
Closed Subscriber Group
Call Segment (followed by an identification Number e.g. CSID1)
Deflected To Number
Dialled Services CAMEL Subscription Information
Event Detection Point
Enhanced Dialled Services
Forwarded To Number
General Packet Radio Service
GPRS Service Switching Function
GPRS CAMEL Subscription Information
GSM Service Control Function
GSM Specialised Resource Function
GSM Service Switching Function
Home Location Register
Initiate Call Attempt
Localised Service Area
Mobility Management event Notification CAMEL Subscription Information
Mobility Management event Notification GPRS CAMEL Subscription Information
Mobile Location Centre
Mobile Number Portability
Mobile Number Portability Signalling Relay Function
Mobile Originated Short Message Service CAMEL Subscription Information
Mobile service Switching Centre
Mobile Terminating in GMSC
Mobile Terminating Short Message Service CAMEL Subscription Information
Network CAMEL Service Information
Network Node Interface
Originating Basic Call State Model
Originating CAMEL Subscription Information
Operator Determined Barring
Operator Specific Service
Packet Data Protocol
Point In Call
Public Land Mobile Network
Serving GPRS Support Node
Service Logic Program Instance
Short Message Control Protocol
Service Management Function
Short Message Relay Service Element
Short Message Service
Short Message Service Centre
Short Message Service CAMEL Subscription Information
Supplementary Service Notification CAMEL Subscription Information
Terminating Basic Call State Model
Terminating CAMEL Subscription Information (in the GMSC)
Trigger Detection Point
Trunk Originated CAMEL Service Information
Transfer Protocol Data Unit
Translation Information Flag
USSD CAMEL Subscription Information
USSD General CAMEL Service Information
User Network Interface
Visitor Location Register
Mobile Terminating in VMSC
VMSC Terminating CAMEL Subscription Information